Cyclische Diazastannylene. - X : Die Kristall- und Molekülstruktur eines Moleküls mit verzerrt-würfelförmigem Sn4N3O-Käfig

Abstract

The crystal and molecular structure of (me3CN)3(me3AlO)Sn4 has been determined from three-dimensional X-ray data (4-circle diffractometer, R=0.048). The crystals are monoclinic, space group P2(1/c), with cell dimensions a=1017.4(5), b=1488.5(7), c=1748(1) pm, beta=91.5(1)° and Z=4. The molecules approach 3m point-symmetry and include a Sn4N3O-cage, the atoms occupying the corners of a distorted cube formed by two, differently sized, interpenetrating concentric tetrahedra of tin and nitrogen/oxygen atoms. The nitrogen atoms are attached to tert-butyl groups, whereas the oxygen atom of the cage acts as a base towards the aluminiumtrimethyl group. Typical bond distances and angles (mean values) are: Sn-N=219.9, Sn-O=220.3 pm; N-Sn-N=81.2°; N-Sn-O=79.0°; Sn-N-Sn=98.8° and Sn-O-Sn=100.2°.